[PATCH v4 01/18] x86, syscalls: Refactor SYSCALL_DEFINEx macros

From: Brian Gerst
Date: Fri Mar 13 2020 - 15:53:22 EST


Pull the common code out from the SYSCALL_DEFINEx macros into a new
__SYS_STUBx macro. Also conditionalize the X64 version in preparation for
enabling syscall wrappers on 32-bit native kernels.

Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
Reviewed-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/include/asm/syscall_wrapper.h | 49 +++++++++++++-------------
1 file changed, 24 insertions(+), 25 deletions(-)

diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index e2389ce9bf58..a1c090bde063 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -21,6 +21,22 @@ struct pt_regs;
,,(unsigned int)regs->dx,,(unsigned int)regs->si \
,,(unsigned int)regs->di,,(unsigned int)regs->bp)

+#define __SYS_STUBx(abi, name, ...) \
+ asmlinkage long __##abi##_##name(const struct pt_regs *regs); \
+ ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO); \
+ asmlinkage long __##abi##_##name(const struct pt_regs *regs) \
+ { \
+ return __se_##name(__VA_ARGS__); \
+ }
+
+#ifdef CONFIG_X86_64
+#define __X64_SYS_STUBx(x, name, ...) \
+ __SYS_STUBx(x64, sys##name, \
+ SC_X86_64_REGS_TO_ARGS(x, __VA_ARGS__))
+#else /* CONFIG_X86_64 */
+#define __X64_SYS_STUBx(x, name, ...)
+#endif /* CONFIG_X86_64 */
+
#ifdef CONFIG_IA32_EMULATION
/*
* For IA32 emulation, we need to handle "compat" syscalls *and* create
@@ -39,20 +55,12 @@ struct pt_regs;
}

#define __IA32_COMPAT_SYS_STUBx(x, name, ...) \
- asmlinkage long __ia32_compat_sys##name(const struct pt_regs *regs);\
- ALLOW_ERROR_INJECTION(__ia32_compat_sys##name, ERRNO); \
- asmlinkage long __ia32_compat_sys##name(const struct pt_regs *regs)\
- { \
- return __se_compat_sys##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));\
- }
+ __SYS_STUBx(ia32, compat_sys##name, \
+ SC_IA32_REGS_TO_ARGS(x, __VA_ARGS__))

#define __IA32_SYS_STUBx(x, name, ...) \
- asmlinkage long __ia32_sys##name(const struct pt_regs *regs); \
- ALLOW_ERROR_INJECTION(__ia32_sys##name, ERRNO); \
- asmlinkage long __ia32_sys##name(const struct pt_regs *regs) \
- { \
- return __se_sys##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));\
- }
+ __SYS_STUBx(ia32, sys##name, \
+ SC_IA32_REGS_TO_ARGS(x, __VA_ARGS__))

/*
* To keep the naming coherent, re-define SYSCALL_DEFINE0 to create an alias
@@ -82,7 +90,7 @@ struct pt_regs;

#else /* CONFIG_IA32_EMULATION */
#define __IA32_COMPAT_SYS_STUBx(x, name, ...)
-#define __IA32_SYS_STUBx(x, fullname, name, ...)
+#define __IA32_SYS_STUBx(x, name, ...)
#endif /* CONFIG_IA32_EMULATION */


@@ -101,12 +109,8 @@ struct pt_regs;
}

#define __X32_COMPAT_SYS_STUBx(x, name, ...) \
- asmlinkage long __x32_compat_sys##name(const struct pt_regs *regs);\
- ALLOW_ERROR_INJECTION(__x32_compat_sys##name, ERRNO); \
- asmlinkage long __x32_compat_sys##name(const struct pt_regs *regs)\
- { \
- return __se_compat_sys##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
- }
+ __SYS_STUBx(x32, compat_sys##name, \
+ SC_X86_64_REGS_TO_ARGS(x, __VA_ARGS__))

#else /* CONFIG_X86_X32 */
#define __X32_COMPAT_SYS_STUB0(x, name)
@@ -192,14 +196,9 @@ struct pt_regs;
* to the i386 calling convention (bx, cx, dx, si, di, bp).
*/
#define __SYSCALL_DEFINEx(x, name, ...) \
- asmlinkage long __x64_sys##name(const struct pt_regs *regs); \
- ALLOW_ERROR_INJECTION(__x64_sys##name, ERRNO); \
static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
- asmlinkage long __x64_sys##name(const struct pt_regs *regs) \
- { \
- return __se_sys##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
- } \
+ __X64_SYS_STUBx(x, name, __VA_ARGS__) \
__IA32_SYS_STUBx(x, name, __VA_ARGS__) \
static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
{ \
--
2.24.1